Dead Coronavirus Particles Muddy the Outcome of Test Results
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Coronavirus patients who remain positive weeks after diagnosis may harbor dead virus particles that can’t be distinguished from infectious ones in standard tests, scientists in South Korea found.
The so-called SARS-CoV-2 virus dies one-to-two weeks after infecting and proliferating inside respiratory cells, doctors at the National Medical Center in Seoul told reporters Wednesday. Pieces of the virus’s genetic material, or RNA, may remain in cells and be detected by a nucleic acid test a month or two after infection, underscoring the limitation of testing, they said.
Some Covid-19 patients have continued to test positive over more than a month, said Peter Collignon, a professor of clinical medicine at the Australian National University Medical School in Canberra, who advises the Australian government on infection control. It’s possible the virus detected in these patients isn’t viable or capable of causing an infection, “but we need better animal models to see if it’s dead or alive,” he said.